1. Field
The present disclosure relates to a fuel storage apparatus.
2. Description of the Related Art
There has been known a fuel storage system in which a separation device is used to separate ethanol-blended gasoline or other raw fuel containing components of different octane numbers into a high-octane fuel containing more components of high octane numbers than the raw fuel and a low-octane fuel containing more components of low octane numbers than the raw fuel and in which the high-octane fuel and the low-octane fuel are selectively supplied to an internal combustion engine (see, for example, Japanese Unexamined Patent Application Publication No. 2011-208541). Such a fuel storage system includes a raw fuel tank that stores the raw fuel, a separation device that separates the raw fuel into the high-octane fuel and the low-octane fuel, and a high-octane fuel tank that stores the high-octane fuel. The separation device includes a heat exchanger (or heater) that heats the raw fuel, a separator that uses a separation membrane to separate the heated raw fuel into the high-octane fuel and the low-octane fuel in accordance with the principle of pervaporation, and a cooler that cools the fuels resulting from the separation process. When the internal combustion engine runs, for example, at a high compression ratio, the fuel storage system can prevent knocking of the engine by increasing the ratio of the high-octane fuel to be supplied to the engine.